2 nights doesn’t seem enough for Vienna, especially if you are flying from the US and will be jet lagged.
Will you have a car? Berchtesgaden is an unusual base for the Salzburg area if relying on public transportation. Beautiful area and you’ll easily find lots to do.
I wouldn’t waste the time going to Munich only for 1 night, then heading right back down to Ortesei. Maybe add another night to Vienna instead.
5 nights is a lot for the Ortesei. I assume you are serious hikers? We were there in June and it was fabulous. Stayed in Santa Cristina. If you like steak, go to La Tambra. Fabulous pear & prosciutto pizza too. Take all the lifts up, you get completely different views from each: Seceda, Col Raiser, Seiser Alm, etc. Truly stunning scenery.
Two nights in Venice is good. Hopefully your flight from Venice doesn’t leave too early. Public transportation to the airport early in the morning can be a challenge.